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DIY Brass Tumbler - Need Help

I thought I would try a fun little project of making my own brass tumbler. Now, I'm scratching my head trying to figure out how to make it work.

I'm using a drill with a rubber mandrel/arbor to turn a belt from a vacuum cleaner, which in turn spins 2 "rollers". This design appeard to work fine until I added the container with the brass and media. At that point, either the rollers turn but the container won't or the mandrel turns but doesn't turn the belt.

The container with the media is just a plastic jar that would hold small snack items. I thought it might just be too smooth so I scuffed it with some 60 grit sandpaper to no avail.

Here are pictures of the setup. Any suggestions are apreciated. Thanks in advance.

You need a way to tension the belt in the rollers. If you put some rubber inner tube bands on your container that will keep it from slipping. You will also need some stops on the rollers to keep the container from "walking" off the end of the rollers.

thanks for the suggestion stonetower. i've got some large rubber bands that will fit nicely around the container, and a cheap metal bookstop to use so it doesnt walk off the rollers. what would you suggest to add tension in the belt? should i remove the belt entirely and just make the drill spin one of the rollers? it seems like i did a test like that and the container didnt spin. but, that might change once i add the rubber bands.

I would just attach the drill to one of the rollers. That's the way many types of tumblers are powered. You could also use a small electric motor and put it next to your roller and run a v belt to one of the roller. If you need tension, make slots for the motors mounting bolts so you can slide the motor away from the roller to create tension on your belt. Your rollers are too smooth. If you use some bicycle innertube on them (if it's the right size for the rollers) or strips of rubber (rubber bands) on your rollers, or rubber bands on your container. It will give your roller to container traction where they contact. The problem is, when you run your machine empty everything works because there isn't any weight or drag. Once you put weight in it, it makes the smooth surfaces slip because of the weight.

But, you have a pretty decent tumbler there. It just needs a little fine tuning. If you want to learn more about tumblers, go to some of the lapidary sites and they have tons of examples that you can use for your design. Google "DIY rock tumbler" or Lapidary Tumblers or even thumbler tumblers and you will find all kinds. Here is a very good sight to use as a starting point .............

I'm a flintknapper (I make arrowheads from stone and glass the way the ancient indians did) and a rock hound and I have several friends that tumble rock (even though I don't). If you can't find any other info on tumbers, shoot me an IM and I'll try to help you out a little more. I'm actaully getting ready to build one myself. A buddy of mine works in an industrial area and they use a mixture of stainless steel pins, squares and trapazoid shaped pieces in their tumblers to clean tools and equipment. He managed to get ahold of a couple of bags of it. I've been reading on Snipers Hyde about using water and a little glass cleaner along with the stainless steal media to clean brass. I really like the idea and want to try it. If you are looking for the stainless steel media, you can pick it up over on Snipers Hyde, they have a link to the company.

P.S. Don't buy a new comercial tumbler. They are way too easy to make and and way too expensive to buy, since they are only two roller, a container and a small motor.

thanks for all the ideas. i originally planned on adding slots to increase tension as the belt stretched, but i nixed them because i was worried about the belt walking due to misalignment. i am guessing a v belt will help with this issue since i want to run the tumbler for lengthy periods. i even bought a countdown timer that i'm going to splice into the power cable.

i am particularly excited because my wife didn't want me to buy a bike i would never use, and after several years i can finally take the inner tubes out of the wheels and actually get some use of the bike instead of just hanging crap from it in my garage. guess i'll show her!

thanks again. i'll get some pics and maybe a video when i wrap it up (don't expect it anytime soon).

FYI for anyone considering doing their own....
$20 for a drill
$10 for a set of rollers
$10 for a container
$2 for a flat belt (not sure about a V, will find out soon)
$5 for a mandrel sandpaper attachment to a drill
$1 in misc nuts and bolts
$0 misc wood i had laying around
$0 for old bookstop i dremeled and used to keep the container from sliding off the rollers
$0 for rubber bands to create friction

i added an optional countdown timer for convenience. that put me over my target of $50. obviously the more your can re-task the more you can save.

You could have used one of those lighting timers (about $8) with on and off pins. You just don't put the on pins in and you can keep ir running for up to 24 hours. I use one to charge an old Craftsman lantern that says not to charge over 30 hours.

my first brass tumbler, i took an old box fan and removed the metal blades, and bolted my container onto the motor, and used a suspended piece of cable on a pulley to keep the weight balanced on both ends, works just as good and fast as my lyman tumbler.

That looks like a variable speed, reversible drill. That means it has brushes. Brushed motors do not survive very long in continuous service. They're not designed for that. The brushes generate a lot of heat and will wear away quickly. Make sure it's on a breaker or fuse barely higher in rating than the current it is supposed to draw, so you don't wind up with an electrical fire if it is left running unattended when the brushes fail. A little reading on types of motors and their intended services might be in order.

The key to making the tumbler work is the water. It keeps the stainless steel media from impacting the brass with any kind of velocity, which keeps the stainless steel from peening the brass. How you turn the container it's in makes no difference. The fan and cement mixers sound like they would work just fine if you already have them on hand. Keep in mind, if you are using a larger container (like a 5 gallon bucket), you are going to have to use more stainless media to get it to clean effectively. About 4-5 pounds in a one gallon container. If you use a 5 gallon bucket, you will more than likely need much more media (15-20 pounds) to make it clean as effectively.

If you work in industrial areas, you can pick up the stainless media much cheaper than what you find on the website I listed. But you only have to buy it once. If you don't loose any of it, it will more than likely work as long as you live, and longer.